Umm... Vector has only one version released per year. 5.8 was 12/06. 5.9 was 12/07. It looks like 6.0 might be 12/08. There are variations on a theme (SOHO, Live, Light) but only one real release. Less than that and we'd be ignored for sure.
I do think the association with Slackware hurts more than it helps. Slackware, to many people means difficult, geeky, unfriendly, and generally a pain in the a**. IT also means fast, stable, and reliable and what Vector Linux does is add the user friendliness and a decent sized repository that Slackware lacks. The problme Vector, Zenwalk, Wolvix, Nonux, etc... all have is getting people to understand that Slackware derivative doesn't necessarily mean just like Slackware. We take all the good that Slackware offers and add what many (most?) people find lacking. It isn't just a Slackware respin the way so many Ubuntu derivatives are just Ubuntu with a new theme and a different package list. Vector is to Slackware what Ubuntu is to Debian and I don't think most people understand that.
Work in progress? All operating systems are perpetual works in progress. They have to be to keep up with new technologies. I don't think VL is any more a work in porgress than other distros. If anything it's less so. We seem to have fewer bugs than Ubuntu in a given release.
Maybe it's time I write a new article, one not limited to Vector...